Resolution
is the amount of detail you can see in an image. You can
enlarge a photograph indefinitely using more powerful
lenses, but the image will blur together and be unreadable.
Therefore, increasing the magnification
will not improve the resolution. This is also known as the
resolving power.

In a compound microscope, the wavelength of the light
waves that illuminate the specimen limits the resolution.
The wavelength of visible light ranges from about 400 to 700
nanometers. The best compound microscopes cannot resolve
parts of a specimen that are closer together than about 200
nanometers.

1 nanometer = 0.001 microns = 0.000001 millimeter =
0.00000004 inch

Dissection Microscope Resolution:

Just like in a compound microscope, the wavelength of
light limits resolution. This microscope does not use light
to see through the specimen, but uses light to aid in
viewing the specimen under magnification. The resolution of
the dissecting or stereoscope is about 120 nanometers.

In a SEM, an electron beam scans rapidly over the surface
of the sample specimen and yields an image of the topography
of the surface. The resolution of a SEM is about 10
nanometers (nm). The resolution is limited by the width of
the exciting electron beam and the interaction volume of
electrons in a solid.

The resolution of a TEM is 1,000 times greater than a
compound microscope and about 500,000 times greater than the
human eye.

Transmission Electron Microscope
Resolution:

In a TEM, a monochromatic beam of electrons is
accelerated through a potential of 40 to 100 kilovolts (kV)
and passed through a strong magnetic field that acts as a
lens. The resolution of a TEM is about 0.2 nanometers (nm).
This is the typical separation between two atoms in a solid.